Dry-kiln.



No. 791,406. PATENTED MAY 30, 1905 B D. CURTIS.

DRY KILN. APPLICATION PHEED AUG. 26, 1904- 2 SHEETS-SHEET 1 ,Efy'zuuui 1 Claw ITO-791,406. A PATENTED MAYAS'O, 1905;

B. D. CURTIS.

DRY KILN.

APPLIOATION FILED AUG. 26, 1904. [q 2 SHEETS-SHEET 2.

. in their movement through the kiln.

f UNITED STATES Patented May 30, 1905.

PATENT OFFICE.

' DRY-KILN.

SPECIFICATION forming part of Letters Patent NO. 791,406, dated May 30, 1905.

i 7 Application filed August 26, l904. Serial No.222,340.

To all whom it may concern:

Be it known that I, BENJAMIN D. CURTIS, a citizen of the United States, residing at Chicago, in thecounty of Cook and State of Illinois, have invented a new and useful Dry- Kiln, of which the following is a specification. I My invention'relates to dry-kilns in which a series of steam-pipes are provided to heat the air and cause it to circulate through the kiln and air-ducts provided therefor; and the objects of my improvements are, first, to provide means whereby the air-currents can be properly and accurately controlled; second, to facilitate the proper heating of the kiln; third, to make a very cheap and efficient construction, and other objects, which will .become apparent from the description to follow.

While 1 have shown and will describe a kiln adapted to be used to dry lumber, it will be understood that it may be used to dry any material.

In kilns to dry lumber it is desirable to have the track or rails upon which the cars loaded with lumber travel inclined from their receiving end down toward the exit end, so that the cars are assisted by'the force of graviitly T e steam-pipes are located as close as convenient below the. tracks, and to economize in space, as well as in the expense of building,

the steam-pipes are supported in any inclined plane, preferably parallel with the track. It is also desirable to submit the lumber in the receiving end of the kiln to a lower degree of temperature than that in theexit end of the kiln. As kilns have heretofore been constructed it was impossible to embody in them both of these desirable features. Either the one or the other had to be omitted. By embodying the construction forming a part of my invention both of these desirable features can be embodied to advantage, thereby increasing the capacity of the kiln.

Another desirable feature to have in a kiln of this class is a system of air circulation capable of being regulated as desired.

A very desirable feature to have in this class of kilns is to be able to regulate the flow of air circulating through that portion of the kiln nearest the entrance which is the coolest the exterior atmosphere.

vided in either side wall.

independently from that air which circulates through that portion nearest the exit and at any desired time permit more or less of the same air or more or less of the exterior air to circulate through the kiln. By the construction embodied in my invention it is possible to have this much-desired air circulation and regulation.

To acquire a greater degree of heat at .one end of the kiln than at the other, I provide a double layer of steam-pipes, one above the other, extending along only a portion of the length of the kiln, and a single layer of steampipes in the balance of the kiln, the pipes being so connected as to compensate for the expansion and contraction of the pipes under the different degrees of temperature. As the pipes are arranged the steam is admitted to the higher ends of the pipe-coils through a header common to all the coils. The steam now travels through the coils in the same direction that the condensed steam does by gravity, first through the single layer of pipesand then through the double layer of pipes. Thus the single layer'of steam-pipes will heat the air within the kiln to a lower degree of temperature than the double layer of steam-pipes will. The lower end of the coils drain into a header common to all the coils located near the exit end of the kiln.

The kiln is provided with a roof and a false roof, the space between the two being used for an air-duct to conduct the air from all parts of the kiln to the roof-vent leading to The false roof is provided with graduated openings to permit the air to pass. Two large air-ducts are provided near the floor of the kiln, one adjacent to either side wall, extending nearly the entire length of the kiln, which communicate with the roof-vent through vertical flues pro- Both of these airducts are provided with openings at intervals near the floor, leading into the kiln. The roof-vent is controlled by a number of hinged valves.

Referring to the drawings forming a part of this specification, Figure l is a vertical longitudinal section through a kiln embodying my invention; Fig. 2 is a similar view,

on an enlarged scale, showing in detail one of the air-valves. Fig. 3 is a cross-section on line 3 3 ofFig. 1, and Fig. 4 is aplan section on line 4 4 of Fig. 1.

Similar reference characters refer to similar parts throughout the several views.

The kiln comprises a floor 5, the side walls 6, preferably built of brick, the roof 7, and the false roof 8. The ends 9 and 10 are, as usual, left open and arranged to be closed by suitable doors 11. An inclined track 12, consisting of three or more rails, extends entirely throughthe kiln longitudinally a short distance above the floor 5. The highest end of the track is at the end 9, where the cars loaded with lumber are introduced, and the lowest end of the track is at the end 10,where the lumber is taken out of the kiln. The track is supported on suitable standards 12, to which are secured the angle-irons 13, which support the steam-pipes. The steam-pipes extend lengthwise of the kiln. are connected to a header 14 near the end 9, to a header 15 near the end 10, and are substantially parallel with the track 12, so that the condensed steam drains by gravity into the header 15. Since the greater amount of heat is required in that half of thekiln nearest the end 10, the steam-pipes nearest the end 9 are single pipes 16 and the pipes nearest the end 10 are double pipes 17 2'. 6., one pipe above anotherthe single pipes 16 and the double pipes 17 being connected by the Ys 18. The pipes17 are connected to the header 15 by means of the short vertical pipes 19, so as to allow the pipes 16 and 17 to individually expand and contract without any danger of causing any breakage. The steam is supplied to the header 14 through the pipe 20, and the condensed steam is drawn off through the pipe 21 after having passed through the steam-trap 22, connected to the header 15.

The false roof 8 is provided with a plurality of holes 23, which are preferably smallest at the receiving end 9 of the kiln and gradually increase in size toward the other end, the largest holes 23 being those at the exit end 10. This arrangement of theseholes 23 causes the greatest amount of air circulation in the hottest end of the kiln. After passing through the holes 23 the air enters the flue or passage 24 between the roofs 7 and 8 and from thence into the roof-ventilator 25. The ventilator which I have shown is made in two sections, one adjacent to either wall 6, so as to leave the space 26 between them to properly drain the highest part of the roof 7. The ventilator consists of a box-like chamber 27, built on the roof 7, said roof 7 forming the floor of the chamber. The wall 6 forms one end of the chamber 27, and a solid wall 28 forms the remaining end of said chamber. The top of this chamber is formed by the ceiling or partition 29, and above this is the roof 30. The

' sides of the chamber 27 are formed by the board partitions or walls 31, which extend from the roof 7 up to within a short distance of the ceiling 29 and are supported by the studding 32. The studding 32 also supports the roof-joist 33, which supports the roof and the ceiling 29. Openings 34 are provided between the ceiling 29 and the top of the walls 31, through which air from the exterior may enter the chamber 27. Additional partitions or walls 35, separated from and preferably parallel with the walls 31, extend from the roof 7 upward to a short distance below the top of the walls 31. The spaces or lines 36 thus formed between the walls 31 and the walls 35 communicate with the flue 24, so that the air from within the kiln can pass through the holes 23, through flue 24, and thence through the fines 36 to the exterior atmosphere. A convenient mode of constructing these parts is as shown in detail in Fig. 2 7. a, the walls 31 are secured to one side of the studding 32, while the walls 35 are secured to the opposite side of the studding 32.

It is necessary to regulate the amount of air passing out through the lines 36 and in through the openings 34, and to accomplish this the horizontal partitions 37 are provided, extending from the tops of the walls 31 to a point about vertically above the tops of the walls 35, occupying the spaces between the studdirrg 32. To the outer free edge of each partition 37 is hinged at 38 a board 39, which acts as a valve to close either the inlet 34 or the outletleading from the flue 36. To move and set the valve 39 in any desired position, a rod 40 is pivotally secured to the valve 39 at 41 and extends down within reach of the operator within the kiln, where it is provided with a ring to fit over any one of a series of pins or any similar arrangement to hold itin place.

Extending nearly the entire length of the kiln, on the floor 5, are two box-fines 42, one adjacent either wall 6. These flues 42 are provided with numerous openings 43, distributed along the entire length of said fines at certain intervals, which may be regular or otherwise. Each flue 42 is connected with its cooperating chamber 27 of a section of the ventilator 25 by one or more vertical lines 44, arranged in the walls 6.

From the above-described construction it will be seen that when the valve 39 is so set as to leave both the outlet from the line 36 and the inlet 34 open the air may pass in through the inlet 34, through chamber 27, line 44, flue 42, and openings 43. Then it may be heated by passing up between the steampipes. Thence it may rise in the kiln, pass through the holes 23 in the roof 8, through flue 24, and, finally, through the fines 36 to the exterior again.

It will be noted that the exits for air from the kiln are immediately below the inlets for air to the kiln. This arrangement is preferred because it is desirable to have a certain amount of the exhausting moist air mixed {with the atmospheric air and returned to the iiln.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

1. Inadry-kiln, a coil of steam-pipe extending longitudinally in said kiln, one end of said coil being a single pipe and the remaining end being a double pipe, the ends of said two pipes terminating in vertical pipes connected to a single pipe or drain. s 2. The combination of a dry-kiln, a longitudinal flue in the bottom of said kiln provided with a plurality of openings communicating with the interior of the kiln, a longitudinal flue in the top of said kiln provided with a plurality of openings communicating with the interior of the kiln, a ventilator on the top of said kiln, a flue forming communication be.- tween the last-named flue and said ventilator and a flue forming communication between the first-named flue and said ventilator.

3. In a dry-kiln,v a ventilator, comprising a fresh-air flue having communication with the interior of the kiln, a moist-air fluehaving communication with the interior of the kiln and a valve for regulating both said flues.

I. In a dry-kiln a ventilator comprising a fresh-air flue having communication with the interior of the kiln and a moist-air flue having communication with the interior of the kiln; said fresh-air flue located immediately above said moist-air flue.

5. In a dry-kiln, a coil of steam-pipe extending longitudinally in said kiln, one end of said coil being a single pipe and the remaining end being a double pipe, the ends of said two pipes terminating in a single pipe or drain.

6. In-a dry-kiln, a series of coils of steampipe arranged on an incline longitudinally in said kiln, each of said coils consisting of one pipe at the high end and two pipes at the low end, a header connecting the high ends and a header connecting the low ends.

7 The'combination ofadry-kiln; a plurality of longitudinal flues in the bottom of said kiln 5 each provided with a plurality of openings communicating with the interior of the kiln,

a longitudinal flue in the top of said kiln provided with consecutivel-y-graduated openings communicating with the interior of the'kiln, 55 a ventilator on the top of said kiln, flues forming communication between the last-named flue and said ventilator and flues forming communication between the first-named flues and said ventilator. 6O

8. The combination ofakiln comprising two side walls two end doors, a roof and a floor; a false roof or ceiling, a flue between the roof proper and said false roof having communication with the interior of said kiln, a series 5 of steam-pipes, means comprising an entrance whereby air from the exterior is admitted to the kiln below the said steam-pipes, and means comprising an exit whereby air from said flue is permitted to exhaust into the exterior at- 7 O mosphere, said entrance being located adjacent and above said exit.

9. The combination of a dry-kiln, a longitudinal flue in the bottom of said kiln provided with a plurality of openings communicating 75 with the interior of the kiln, a longitudinal flue in the top of said kiln provided with a plurality of openings communicating with the interior of the kiln, a flue having an exit forming communication between the last-named 80 flue and the exterior, a flue having an entrance forming communication between the firstnamed flue and the exterior and a valve for controlling said exitand said entrance.

In testimony whereof Ihave signed my name 5 to this specification, in the presence of two subscribing witnesses, this 18th day of August, 1904, at Chicago, Illinois.

, BENJAMIN D. CURTIS.

Witnesses:

R. J. JAOKER, F. J. Sol-1A1), Jr. 

